It is the common industrial practice to randomly test electrical components of the type that are used, for example, in motor vehicles, for reliability and failure. Every component is not so tested; defective components hence find their way into the marketplace. Small numbers of components can be individually tested by placing them in ovens or refrigerators with appropriate electrical leads connected to monitoring instruments. Large numbers of electrical components cannot be efficiently tested in this manner. Visual inspection of electrical components during manufacture and upon completion has improved product reliability. However, visual inspections are not done under adverse environments, such as hot and cold temperatures, and do not monitor the electrical operation or integrity of components.